This is an episode basically where Carter shows he is a lot smarter than what he is given credit for.
You have all these scientists who think they know everything and one very annoying deputy in Jo, yet you have an episode like this where no one can use simple common sense to solve a problem? Carter is such an under-appreciated character this what makes him stand out more than anybody else in the show.
So a couple of people are dying under mysterious circumstances: One drowned in her car, another in the bathroom but how? Could it be another Eureka science experiment gone wrong?
Well if you've watched the show with any regularity, you can guess what the answer to that is.
Even Fargo who tried to act like a know it all medical examiner couldn't fathom that these people deaths were caused by exposure due to a rather freaky science experiment.
Thus it's not by coincedence that the writers had Carter as the one who put everything together. Granted he is the law in the town but as much you have all these egos and scientists that you think the answer would come easier.
The writers then really develop Carter well from Season to Season not just as the hero but as the next door type of guy whom you'd probably under-appreciate until something terrible happens.
The other part of the show was the expect death of Clone Kim. Deacon had to decide to let her go. She was going to die but could he interrupt the download of the data which would probably accelerate the process?
Great episode. Great acting all around. Carter is the said hero. You can't ask for anything more.